Method of producing lock key blanks

ABSTRACT

Lock key blanks are produced from an elongated strip of key material having a width at least as great as the length of a transversely extending key pair arranged with their shanks overlapping longitudinally of the strip and arranged with their bows alternately disposed adjacent opposite edges of the strip. Production is accomplished by performing simultaneously in time and successively in the length of the strip certain forming and cutting operations shaping and removing from the strip different areas defining fractional parts of the boundaries of the key pair, also performing operations coining and grooving the potential key pair, and finally performing cutting operations severing the boundaries of portions remaining integral with the strip to free fully formed, separate key pair blanks from the strip.

22 Filed:

United States Patent, 1191 Elder et al. I Y

[ METHOD OF PRODUCING LOCK KEY BLANKS [75] Inventors: George Elder, Woodside; Hans F.

Lehnhoff, Morage, both of Calif.

[73] Assignee: Schlage Lock Company, San

Francisco, Calif.

Jan. 26, 1973 [211 App1.No.:'326,827

[52] Cl 72/324, 76/110, 113/116 BB,

51 Int. Cl. 'G0lf 23/02 58 Field of Search 76/110; 29/557, 180 A, 29/1935, DIG. 20, DIG. 37; 113/116 v, 116

[56] References Cited UNITED STATES PATENTS I I 225,227 3/1880 Mathes 76/110 756,585 4/1904 Clark 76/110 774,242 1 1/1904 Gates 76/110 1,517,177 11/1924 Stone 76/110- 2,105,099 l/l938 Schuyler 76/110 111] 3,823,596 1 July 16, 1974 Brunner .Q 76/110 Demrick 76/110 ,Primary Examiner.Charles W. Lanham Assistant Examiner-lames R. Duzan Attorney, Agent, or Firm--Lothrop & West 5 7] ABSTRACT Lock key blanks are produced from an elongated strip of key material having a width at least as great as the length of a transversely extending key pair arranged with their shanks overlapping longitudinally of the strip and arranged with their bows alternately disposed adjacent opposite edges of the strip. Production is accomplished by performing simultaneously in time and successively in the length of the strip certain forming and cutting operations shaping and removing from the strip different areas defining fractional parts of the boundaries of the key pair, also performing operations coining and grooving the potential key pair, and finally perform ng cutting operations severing the boundaries of portionsremaining integral with the strip to free fully formed, separate key'pair blanks from the strip.

. 4 Claims, 4 Drawing Figures mzmmwu 3.823.596

SHEET 1 8F 2 ,rIG-Z 1 METHOD OF PRODUCING LOCK KEY BLANKS In the quantity production of locks such as building locks, operable by means of keys, usually metallic keys, it is necessary to provide a large number of lock keys all having the same or generally similar bow and shank outline configuration and having a selected crosssection in the shank portions thereof. The shanks are serrated, bitted along an edge to engage and actuate related locks. It is usually desirable to perform the bitting step separately, but it is helpful to make the key blanks (the keys without bitting) in large quantities. It is customary to provide the shank cross-section, usually a family of grooves and ridges running longitudinally of the key, by some sort of metal chip cutting, such as milling or the like. It is advantageous to provide the desired cross-sectional shank contour without the necessity of removing substantial material therefrom and particularly without chip cutting It is therefore an object of the invention to provide a method of producing lock key blanks in which the key bow portions are all substantially identical and the key shank portions are uniformly furnished with a predetermined cross-sectional configuration readily available for hitting.

Another object of the invention is to provide a method of producing lock key blanks which is economical of the lock key material and which is effective to produce keys without substantial loss of material, particularly loss due to chip cutting operations.

A further object of the invention is to provide a method of producing lock key blanks in which the material of the key blanks may be worked during the forming or producing operation.

Another object of the invention is to provide a method of producing lock key blanks in large quantities in a short space of time.

A further object of the invention is to provide a method of producing lock key blanks in which separate handling of the potential key blanks between operations is eliminated.

A further object of the invention is in general to provide an improved method of producing lock key blanks.

Other objects of the invention, together with the foregoing, are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

FIG. 1 is a diagrammatic view showing a portion of a machine effective to operate dies pursuant to the requirements of the method in order to produce the desired key blanks from strip stock;

FIG. 2 is a cross-section, the plane of which is indicated by the line 2--2 of FIG. 1;

FIG. 3A is a plan of a portion of a key blank strip as it receives successive steps of treatment during the process; and

FIG. 3B is a continuation of FIG. 3A, the left end of FIG. 38 being contiguous to the right end of FIG. 3A and shows further steps in the performance of the process.

The process of the invention can be practiced in a number of different ways and on a number of objects comparable to key blanks, but for illustration, it is described herein in connection with the production of finished key blanks such as are disclosed toward the right hand end of FIG. 3B. A typical finished key blank 6 has a bow 7 (shaded) and a shank 8. The key blank has an opening 9 for hanging the key or putting it on a key ring and usually carries on each side a legend 11 such as the name of the maker. The shank 8 customarily has certain longitudinal ridges 12 and grooves 13 on both sides defining an irregular and special shank cross-section to fit a special group of locks. The blank has no notches or bits but does have a longitudinal edge 14 provided as a site for notches subsequently cut after the key blank has been finished. The shank also has a longitudinal bearing edge 25 and a point. The thickness of the key blank is substantially uniform throughout except for whatever depressions and raised portions might be provided at the legend 11 or in the surrounding areas of the bow 7 or except for the ridges 12 and grooves 13 in the shank 8.

Pursuant to the method and in order to provide a key blank of the noted sort, it is preferred to conduct the entire operation on a press 16 (FIG. 1) or a comparable machine having a stationary base 17 and a ram 18 reciprocable vertically toward and away from the base 17. The base 17 supports a special die 19 whereas the ram 18 supports a complementary punch 21. When the ram 18 is driven by any appropriate means (not shown) the punch is reciprocated repeatedly in a vertical path. The punch 21 and die 19 cooperate to form and cut material disposed between them.

For this purpose there is fed into the machine, from the left of FIG. 1, a strip 22 of material. The feed mechanism is well known and is not shown, but in synchronism withthe press operation the material is fed intermittently in equal steps.

The material fed is appropriate for the manufacture of lock key blanks and is customarily metal of the brass family or of the nickel-silver family having a thickness approximately that of the key blank to be furnished. The length of the strip is suitable for a production run. The strip width W, particularly as shown in FIG. 3A, is at least as great as, and preferably is slightly more than, the width of a pair of adjacent key blanks such as 6A and 68 (FIG. 3B) when those blanks are arranged in a set position with their center lines 26 and 27 parallel to each other transversely of the strip 22 and at right angles to the direction of advance of the strip as indicated by the arrow 29. The key blanks 6A and 6B in set position are disposed so that their shanks 8 are overlapped when considered in the direction of advance of the strip and are reversed, or upright and inverted, as to their side faces. The bows 7 are staggered and reversed each with respect to the other and come quite close to the opposite longitudinal edges 31 and 32 of the strip 22.

In this way successive key blanks 6A and 68 can be considered as grouped in repetitive pairs. This pairing puts the blanks quite close to each other with only a relatively small amount of intervening and surrounding strip material.

A strip 22 of the desired width, length and thickness is introduced and fed between the punch 21 and the die 19. As shown at the left end of FIG. 3A, the strip is initially formed at a first station A that is duplex and is illustrated by center lines 26A and 26B joined by a ligament 26C to indicate that duplex operations along the center lines 26A and 26B are performed by the punch and die at the first station A.

In this instance, the operation at station A provides a pair of mutually staggered, individually centered, op-

positely directed, identical legends or indicia 11. This operation is a coining operation since it displaces the material of the strip without removing any and embosses as to portions raised from their surroundings and debosses as to portions depressed below adjacent areas.

Usually the maker-ls name or trademark is coined. The cross-hatched areas, such as 26D and 26E, at the stations illustrate the approximate area of the strip worked upon at those stations. They also illustrate duplex or paired operations longitudinally staggered from each other but equally spaced from the longitudinal center line of the strip.

Upon the opening of the die set after the operation at the first station A, the strip 22 is advanced to a second station B. This is a standard increment or feed or longitudinal distance from station A but is one in which no forming operation occurs. Next, the strip 22 advances the unit amount to station C whereat the punch 21 encounters the strip 22 so as to sever the margins or outline of an area 36 having sides 37 and 38 each defining a similar portion of the ultimate boundaries of the potential blanks 6A and 6B. A single area is referred to as a first area and is removed at station C.

When the die is again opened the strip advances to the next station D, a unit distance away. The first cut portion 36 having been knocked out of the strip, there is left a corresponding opening 40 therethrough, as is shown at station D, which is void. At the next increment or step, the station E, the punch descends and cuts the boundaries of another area 39, similar to the area 36, and having boundaries 41 and 42. The boundary 41 defines an equivalent or corresponding portion of a key blank 6B at the next station while the boundary 42 defines a portion of the key blank 6A at the station E. These portions are in addition to the sides 37 and 38 previously defined by cutting. The area 39 is punched out at station E and the strip then advances the unit amount to station F. With the key 6B in this position the descending punch forms the edge 42 of the key and a void 45 remains in the strip.

At the next strip advance, station G, a punch cuts and forces out an area 46, referred to as a second area, extending longitudinally of the strip and disposed across the end of the shank of the key blank 6A.

An advance is made to the next station H, the strip progressing the unit amount. At station H the punch descends and cuts from the strip a similar, spaced area 47, a second area, also extending longitudinally of the strip and disposed across the end of the shank of the key blank 6B. In fact, the areas 46 and 47 interconnect the voids 40 and 45, thus detaching each key shank on three sides but leaving it still attached to the strip on the fourth side. The areas 46 and 47 are symmetrical about the longitudinal center line of the strip, as before, but are staggered in a longitudinal direction.

The strip again advances the unit amount to the next station I, the previously removed areas 46 and 47 leaving connecting end voids 48 and 49. At the station I when the punch descends, the key shank 6A is subjected to coining pressure over the area 51. This operation provides the longitudinal ridges l2 and grooves 13 extending more or less the full length of the shank. The ridging and grooving operation does not remove any material but displaces the material of the strip not only in a vertical direction (normal to the planar surfaces of the strip) but also in a longitudinal and perhaps transverse direction. The resulting laterally extended area of the key shank (as shaded at station I) may be in excess of the desired final dimensions. At the next station, J, the punch performs a similar coining operation on the blank 6B as shown by the shaded area 52 at that station, the operation being identical to that performed at station I on the blank 6A.

The strip then advances the unit amount from station J to station K (FIG. 3B) and a duplex operation is performed. In this instance, another pair of second areas 56 and 57 are cut and removed from the strip to define appropriate boundaries for both of the openings 9 indicated by the voids 58 and 59 for the individual blanks.

When the strip has advanced to station L the descending punch cuts the boundary of an area 61 which is removed. At the next station, M, the boundaries of a similar second area 62 are cut and the resulting slug is removed. The areas 61 and 62 are staggered longitudinally and are symmetrical with respect to the longitudinal center line of the strip. They provide boundaries 63 and 64 for the ends of the key pair and afford the finished end shape.

The next advancement of the strip to station N shows voids 66 and 67 due to previous removal of the areas 61 and 62.

Descent of the punch at station N is effective to cut and dislodge a first or single area 68 as a reenlargement and final shaping of the void 45, reduced at stations I and J, to provide final dimensions for the edge 14 of the adjacent blank 6A and of the corresponding edge of the blank 68 at the next station.

At the next station, 0, the operation is repeated to provide the similaredge 14 for the trailing key blank 6B. Station P, the next in order, is blank.

In the advancement to the next station Q the strip is positioned for the punch to make a cut 69 corresponding to the remaining outline of the bow of but one of the blanks 6B, the blank 6A not being operated upon at station Q. Actually, the blank 68 is cut at the bow and is displaced from the strip but is returned to the plane of the strip and is frictionally retained therein for transport to adjacent station R. Thereat a particular punch 71 (FIG. 1) in descending knocks out the completely severed key blank 6B which falls into a chute 72 for subsequent separate handling. Also at station R, the main punch cuts the bow outline 69 of the blank 6A which is displaced from and returned to the strip. At station S the blank 6A is knocked out by a special punch 73 into a chute 74 for separate handling.

In the foregoing description the cutting and displacing events at the individual stations are described as they occur successively when considered relative to the longitudinal dimension or length of the progressing strip 22. However, it is preferred that all of the individual punches be situated on the main punch 21 to meet with corresponding cavities in the lower die 19 at the same time so that all of the operations disclosed in FIGS. 3A and 3B occur simultaneously during one cycle of the machine 16. This is readily accomplished, despite variations in the nature of the steps performed at the different, individual stations.

In some of the stations the die 19 may be provided with a yieldable support 76 held normally in its uppermost position by a relatively strong die spring 77. When the local punch on the ram 18 descends against the local portion of the strip 22 to displace it, the yielding portion 76 descends in order to insure that the severable portion is actually displaced. Then the displaced part is restored by the spring 77 to the plane or body of the strip for advancement.

in this fashion, material for key blanks is fed into one end of the machine, and in each operation of the machine a number of partially completed blanks are severed, formed, trimmed and marked and a pair of completed key blanks is discharged. No further mechanical operation is needed on any one of the blanks and all handling of the blank pairs is by normal advancement of the strip 22 intermittently through the machine.

Customarily, the discharged key blanks are subsequently bitted in accordance with an appropriate scheme or program in entirely different machinery. If, however, a large number of key blanks are to have similar bittings, then it is feasible to have a station provided with an appropriate punch shaped to cut away bit areas of each key blank along the edge 42 thereof so that the finally discharged key pairs are immediately ready for use in corresponding locks and do not require separate notching or bitting.

What is claimed is:

l. A method of forming key blanks having integral bow and shank portions from a strip of deformable material wherein said strip is advanced in intermittent cycles to position sequential portions thereof in successive operating stations and wherein a plurality of forming operations are simultaneously performed on said portions of said strip at a plurality of said stations at each of said cycles, and including the steps of:

performing said forming operations on each sequential strip portion in the sequence of first removing material from said strip to leave shank portions of alternate ones of said blanks integral with the remainder of said strip and extending transversely across said strip from alternate sides thereof; then forming the material of said shank portions to final configuration by spreading the material thereof, by forming grooves and ridges extending therealong and by trimming; and thereafter severing a bow portion, integral with each shank portion, from said strip to release successive key blanks.

2. The method of claim 1 wherein said material is removed from said strip entirely within the side edges thereof.

3. The method of claim 1 wherein said material is removed in at least two successive steps, first removing material from along the sides of said shanks and then from the end portions of said shanks.

4. The method of claim 1 wherein said step of forming grooves and ridges on said shank portions is performed by a die stamping step. 

1. A method of forming key blanks having integral bow and shank portions from a strip of deformable material wherein said strip is advanced in intermittent cycles to position sequential portions thereof in successive operating stations and wherein a plurality of forming operations are simultaneously performed on said portions of said strip at a plurality of said stations at each of said cycles, and including the steps of: performing said forming operations on each sequential strip portion in the sequence of first removing material from said strip to leave shank portions of alternate ones of said blanks integral with the remainder of said strip and extending transversely across said strip from alternate sides thereof; then forming the material of said shank portions to final configuration by spreading the material thereof, by forming grooves and ridges extending therealong and by trimming; and thereafter severing a bow portion, integral with each shank portion, from said strip to release successive key blanks.
 2. The method of claim 1 wherein said material is removed from said strip entirely within the side edges thereof.
 3. The method of claim 1 wherein said material is removed in at least two successive steps, first removing material from along the sides of said shanks and then from the end portions of said shanks.
 4. The method of claim 1 wherein said step of forming grooves and ridges on said shank portions is performed by a die stamping step. 